How to Change Out a P-Trap

Throughout the home, there are many plumbing components that help keep sinks and showers operating properly. Many of these parts go unnoticed in day-to-day life. However, when something goes wrong, homeowners quickly discover how many parts make up their plumbing system.

One crucial part of any sink is called a P-trap or sink trap. This plumbing fixture is located underneath the kitchen and bathroom sink and serves an incredibly important purpose. Over the years, a P-trap can become damaged or clogged, at which point it must be cleaned or replaced. In this guide, learn everything you need to know about P-traps, including a step-by-step guide for changing out a P-trap and tips for cleaning sink traps.

What Is a P-Trap?

A P-trap is a curved drain pipe that is located underneath kitchen and bathroom sinks. P-traps create a U-bend in drain piping. This bend is designed to serve two important purposes. First and foremost, it prevents noxious gases from entering the home. Because a drain pipe is connected to a septic tank or sewer system, all the gases, such as methane, located in this system would be able to enter the home without the unique design of a P-trap.

P-traps also prevent you from losing small items in their septic or sewer systems. When something falls down the drain, such as a ring, it will be trapped in the P-trap. From here, it is much easier to retrieve the item than it would be if the drain pipe led directly into the waste system.

Sink traps can be designed from numerous materials, including PVC, ABS, brass, copper, or chrome. They are available in multiple sizes, designed to fit snugly onto bathroom and kitchen sink drains.

Most P-traps are designed with slip fittings that connect the individual components of the pipe together. This makes it easy to take apart and assemble a P-trap. In some cases, these components might be glued together with solvent or soldered together.

Signs That Indicate You Need to Change a P-Trap

How does one know when it is time to change out a P-trap? There are numerous signs that indicate it might be time to replace a P-trap, including the following:

• The P-trap has corroded: This is the most common reason for older P-traps to need to be replaced. Often made of metals that rust and corrode, these P-traps will begin to leak.
• The sink trap is clogged: Over the years, everything from soap to food particles can accumulate in P-traps. This is particularly common in the kitchen, where the sink sees more debris. When a P-trap is clogged, the drain will either slowly drain after every use or stop draining entirely.
• 
  There is a bad odor coming from the sink drain: When a P-trap no longer works well, it will allow gases from the septic or sewer system to rise into the home through the drain. This can lead to a bad odor, which indicates the P-trap needs replacement.
• The P-trap doesn't fit a new sink: When installing a new sink, an existing P-trap might not be the right size or configuration. In this case, updating to a P-trap designed for the new sink style will be necessary.
• The P-trap doesn't match the room's design: For sinks where the plumbing is exposed, you might decide to swap out a P-trap to better match the interior design. For example, a white PVC P-trap that isn't hidden by a vanity can become an eyesore.

Step-by-Step Guide for Changing a P-Trap

Replacing a P-trap is generally not complex and can be done as a simple DIY project. Follow these steps to swap out one P-trap with another.

1. Turn off the water to the bathroom.
2. Place a bucket under the existing P-trap.
3. Unscrew the nuts that are connecting the P-trap middle section to the tail pipe (the pipe coming out of the sink) and to the drain pipe (the pipe connecting to the sewer or septic line). In the case of a plastic P-trap, nuts can often be unscrewed by hand. For other styles, it might be necessary to use a pair of pliers.
4. Pull the P-trap out of the tailpipe and drain pipe. Allow any water in the P-trap to drain into the bucket. If anything was caught in the P-trap, it, too, would drain into the bucket.
5. For those who plan to replace the tailpipe and drain pipe, these will need to be removed next. For those who only wish to replace the center portion, the piece can now be installed.
6. In most cases, the P-trap will come equipped with a washer that rests between the P-trap and the tailpipe. Make sure this is in place before tightening the nuts on the new P-trap section.
7. Start by connecting the P-trap to the tailpipe. Next, align the P-trap to the drain pipe. This may require cutting the P-trap to the right length, depending on whether or not the components came together as a kit.
8. Turn back on the water and check for leaks by running the faucet for about a minute.

Keep in mind that installation can vary depending on the type of P-trap purchased. Always refer to the installation sheet that comes with the product.

When to Clean a P-Trap

In some cases, it is not necessary to replace a P-trap. Simply cleaning out the sink trap will solve the issue. For clogs, it can be helpful to start with a deep cleaning rather than immediately replacing the part.

To clean a P-trap, you will disassemble the P-trap the same way you would for replacement. Instead of installing a new P-trap, simply clear out the P-trap using a drain stick or brush.

To prevent large clogs from occurring, most plumbers recommend you clean out P-traps around four to six times a year.

Tips When Shopping for a New P-Trap

Whether a P-trap has corroded and is leaking or you're simply tired of staring at an unappealing pipe when shopping for a new P-trap, it is important to keep two things in mind:

1. The size of the P-trap: Most sinks have a tailpipe fitting between 1 ½ to 1 ¼ inches in diameter. Always measure this before purchasing a new P-trap to ensure it will fit.
2. The style of the P-trap: P-traps come in a variety of styles. The right one will depend on the space and the style of the room. For exposed bathroom P-traps, picking a quality finish is a must. For compact vanities, a P-trap will need to be small enough to fit under the sink.

If you're seeking a new P-trap, Kingston Brass is the perfect place to shop. Kingston Brass carries an array of P-traps designed to match any style. From elevated vintage designs with a brushed brass finish to sleek polished chrome, find the right P-trap today through Kingston Brass' extensive catalog.